Chuck jaw



P. FRSTER June 9, 1925.

CHUCK JAW Filed Feb. 13', 1922 -2 sheets-sheet 1 hm I P. FQRSTER CHUCK JAW `.luna 9, 1925.

F1106 Feb. 13, 1922 2 Shasta-Sheet 2 l Patented June 9, 1925.

UNITED STATES PATENT OFFICE.

PAUL FRSTER, OF NUREMBERG, GERIVIANY, ASSIGNOR TO AKTIENGESELLSCHAFT VQRM. ADOLF FINZE 8c CO.,

or NUREMBERG, GERMANY.

CHUCK JAW.

Application filed February 13, 1922. Serial No. 536,376'.

new and useful Improvements in Chuck Jaws, of which the following is a specification.

In chuck jaws of known construction, illustrated in Figure l, consisting of several 10 parts pivotally connected the one with the others and in which the aws are mounted after themanner of a weighing scale, the jaws A which are designed to hold the work piece, as well as the jaws B and B2, which serve to guide the clamping jaws, are arranged symmetrically with regard to the axis of the spindle X Y. The take-up jaws B and B2 can be guidedin a number of take-up jaws of larger size, for instance C and C2 which themselves are guided in ranged symmetrically the central axis ofl larger jaws D and so forth so that several sets of identical jaws are produced. All the take-upl jaws of one set, viz, all the jaws A, B or C are of the same diameter and arthe vice.

On the drawings Fig. 1 shows in plan view the arrangement of known construction designed to be improved. v

Fig. 2 shows in plan view the arrangement improved according to this invention.

In the arrangement of the known type, shown on Fig. l, the inconvenience makes itself felt, in that an unelastic surface F of one of th'e larger take-up jaws,` for instance of the jaws @D in the central axis X Y, cannot be avoided. If the work piece W to be clamped were shaped as shown in Fig. l and so long as its edges would get into the range of this surface F, it would be locked by this rigid surface F before the clamping jaws Vproper A, which serve for the clamping, could come 'in contact with the work piece W at these points, as illustrated in Figure l. The range of clamping was thus limited in an undesirable manner as regards the advantages resulting from the complete embracing of the Vwork piece by the jaws A. This inconvenience can be avoided if, according to the invention, the arrangement is improved as shown on Fig. 2.

A are the clamping jaws (first set) which are designed to come in contact with the work piece W. They are pivotally mountedl in larger take-up jaws B B2 and Bi' (second set of jaws) which themselves can ie guided, if required, in a third set of takeup jaws C and C2 of still larger size, and so forth. The novelty consists in having the jaws, for instance, of the set C and G2 designed to guide the sets B', B2, B3 of various diametersand eccentrically inserted into' one another and having the centers m, n of their circular guide tracks situated on a straight line inclined with regard to theaxis Z-Z of the chuck. The axis Z-Z stands perpendicular to the spindle X, Y. In this manner the jaws of the same set are of diiierent diameters as can be seen from the jaws C and C2 of the third set of jaws on Fig. 2, which shows that in the manner described it has become possible to bring all the jaws A in contact with the work piece W, which is not the case in the form of construction shown on Fig. 1.

A chuck jaw comprising in combination different sets of oscillatingly mounted jaws, the first inner set consisting of aws of equal diameter being adapted to engage and holdv the work piece, the jaws of one of the two other inner sets of aws being of different diameters and seat-ed one within the other, the 'inner one being of a diameter less than the diameter but greater than the radius, of the outer one in which it is seated and guided.

'In testimony whereof I ailix my signature in presence of two witnesses;

PAUL FORSTEB. Witnesses:

ALEXANDER Dn Soro, ALEXIS v. GHrLrPPoFF. 

